1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * bio-integrity.c - bio data integrity extensions 4 * 5 * Copyright (C) 2007, 2008, 2009 Oracle Corporation 6 * Written by: Martin K. Petersen <martin.petersen@oracle.com> 7 */ 8 9 #include <linux/blk-integrity.h> 10 #include "blk.h" 11 12 struct bio_integrity_alloc { 13 struct bio_integrity_payload bip; 14 struct bio_vec bvecs[]; 15 }; 16 17 /** 18 * bio_integrity_free - Free bio integrity payload 19 * @bio: bio containing bip to be freed 20 * 21 * Description: Free the integrity portion of a bio. 22 */ 23 void bio_integrity_free(struct bio *bio) 24 { 25 kfree(bio_integrity(bio)); 26 bio->bi_integrity = NULL; 27 bio->bi_opf &= ~REQ_INTEGRITY; 28 } 29 30 void bio_integrity_init(struct bio *bio, struct bio_integrity_payload *bip, 31 struct bio_vec *bvecs, unsigned int nr_vecs) 32 { 33 memset(bip, 0, sizeof(*bip)); 34 bip->bip_max_vcnt = nr_vecs; 35 if (nr_vecs) 36 bip->bip_vec = bvecs; 37 38 bio->bi_integrity = bip; 39 bio->bi_opf |= REQ_INTEGRITY; 40 } 41 42 /** 43 * bio_integrity_alloc - Allocate integrity payload and attach it to bio 44 * @bio: bio to attach integrity metadata to 45 * @gfp_mask: Memory allocation mask 46 * @nr_vecs: Number of integrity metadata scatter-gather elements 47 * 48 * Description: This function prepares a bio for attaching integrity 49 * metadata. nr_vecs specifies the maximum number of pages containing 50 * integrity metadata that can be attached. 51 */ 52 struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio, 53 gfp_t gfp_mask, 54 unsigned int nr_vecs) 55 { 56 struct bio_integrity_alloc *bia; 57 58 if (WARN_ON_ONCE(bio_has_crypt_ctx(bio))) 59 return ERR_PTR(-EOPNOTSUPP); 60 61 bia = kmalloc(struct_size(bia, bvecs, nr_vecs), gfp_mask); 62 if (unlikely(!bia)) 63 return ERR_PTR(-ENOMEM); 64 bio_integrity_init(bio, &bia->bip, bia->bvecs, nr_vecs); 65 return &bia->bip; 66 } 67 EXPORT_SYMBOL(bio_integrity_alloc); 68 69 static void bio_integrity_unpin_bvec(struct bio_vec *bv, int nr_vecs) 70 { 71 int i; 72 73 for (i = 0; i < nr_vecs; i++) 74 unpin_user_page(bv[i].bv_page); 75 } 76 77 static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip) 78 { 79 unsigned short orig_nr_vecs = bip->bip_max_vcnt - 1; 80 struct bio_vec *orig_bvecs = &bip->bip_vec[1]; 81 struct bio_vec *bounce_bvec = &bip->bip_vec[0]; 82 size_t bytes = bounce_bvec->bv_len; 83 struct iov_iter orig_iter; 84 int ret; 85 86 iov_iter_bvec(&orig_iter, ITER_DEST, orig_bvecs, orig_nr_vecs, bytes); 87 ret = copy_to_iter(bvec_virt(bounce_bvec), bytes, &orig_iter); 88 WARN_ON_ONCE(ret != bytes); 89 90 bio_integrity_unpin_bvec(orig_bvecs, orig_nr_vecs); 91 } 92 93 /** 94 * bio_integrity_unmap_user - Unmap user integrity payload 95 * @bio: bio containing bip to be unmapped 96 * 97 * Unmap the user mapped integrity portion of a bio. 98 */ 99 void bio_integrity_unmap_user(struct bio *bio) 100 { 101 struct bio_integrity_payload *bip = bio_integrity(bio); 102 103 if (bip->bip_flags & BIP_COPY_USER) { 104 if (bio_data_dir(bio) == READ) 105 bio_integrity_uncopy_user(bip); 106 kfree(bvec_virt(bip->bip_vec)); 107 return; 108 } 109 110 bio_integrity_unpin_bvec(bip->bip_vec, bip->bip_max_vcnt); 111 } 112 113 /** 114 * bio_integrity_add_page - Attach integrity metadata 115 * @bio: bio to update 116 * @page: page containing integrity metadata 117 * @len: number of bytes of integrity metadata in page 118 * @offset: start offset within page 119 * 120 * Description: Attach a page containing integrity metadata to bio. 121 */ 122 int bio_integrity_add_page(struct bio *bio, struct page *page, 123 unsigned int len, unsigned int offset) 124 { 125 struct request_queue *q = bdev_get_queue(bio->bi_bdev); 126 struct bio_integrity_payload *bip = bio_integrity(bio); 127 128 if (bip->bip_vcnt > 0) { 129 struct bio_vec *bv = &bip->bip_vec[bip->bip_vcnt - 1]; 130 131 if (bvec_try_merge_hw_page(q, bv, page, len, offset)) { 132 bip->bip_iter.bi_size += len; 133 return len; 134 } 135 136 if (bip->bip_vcnt >= 137 min(bip->bip_max_vcnt, queue_max_integrity_segments(q))) 138 return 0; 139 140 /* 141 * If the queue doesn't support SG gaps and adding this segment 142 * would create a gap, disallow it. 143 */ 144 if (bvec_gap_to_prev(&q->limits, bv, offset)) 145 return 0; 146 } 147 148 bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset); 149 bip->bip_vcnt++; 150 bip->bip_iter.bi_size += len; 151 152 return len; 153 } 154 EXPORT_SYMBOL(bio_integrity_add_page); 155 156 static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec, 157 int nr_vecs, unsigned int len, 158 unsigned int direction) 159 { 160 bool write = direction == ITER_SOURCE; 161 struct bio_integrity_payload *bip; 162 struct iov_iter iter; 163 void *buf; 164 int ret; 165 166 buf = kmalloc(len, GFP_KERNEL); 167 if (!buf) 168 return -ENOMEM; 169 170 if (write) { 171 iov_iter_bvec(&iter, direction, bvec, nr_vecs, len); 172 if (!copy_from_iter_full(buf, len, &iter)) { 173 ret = -EFAULT; 174 goto free_buf; 175 } 176 177 bip = bio_integrity_alloc(bio, GFP_KERNEL, 1); 178 } else { 179 memset(buf, 0, len); 180 181 /* 182 * We need to preserve the original bvec and the number of vecs 183 * in it for completion handling 184 */ 185 bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs + 1); 186 } 187 188 if (IS_ERR(bip)) { 189 ret = PTR_ERR(bip); 190 goto free_buf; 191 } 192 193 if (write) 194 bio_integrity_unpin_bvec(bvec, nr_vecs); 195 else 196 memcpy(&bip->bip_vec[1], bvec, nr_vecs * sizeof(*bvec)); 197 198 ret = bio_integrity_add_page(bio, virt_to_page(buf), len, 199 offset_in_page(buf)); 200 if (ret != len) { 201 ret = -ENOMEM; 202 goto free_bip; 203 } 204 205 bip->bip_flags |= BIP_COPY_USER; 206 bip->bip_vcnt = nr_vecs; 207 return 0; 208 free_bip: 209 bio_integrity_free(bio); 210 free_buf: 211 kfree(buf); 212 return ret; 213 } 214 215 static int bio_integrity_init_user(struct bio *bio, struct bio_vec *bvec, 216 int nr_vecs, unsigned int len) 217 { 218 struct bio_integrity_payload *bip; 219 220 bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs); 221 if (IS_ERR(bip)) 222 return PTR_ERR(bip); 223 224 memcpy(bip->bip_vec, bvec, nr_vecs * sizeof(*bvec)); 225 bip->bip_iter.bi_size = len; 226 bip->bip_vcnt = nr_vecs; 227 return 0; 228 } 229 230 static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages, 231 int nr_vecs, ssize_t bytes, ssize_t offset) 232 { 233 unsigned int nr_bvecs = 0; 234 int i, j; 235 236 for (i = 0; i < nr_vecs; i = j) { 237 size_t size = min_t(size_t, bytes, PAGE_SIZE - offset); 238 struct folio *folio = page_folio(pages[i]); 239 240 bytes -= size; 241 for (j = i + 1; j < nr_vecs; j++) { 242 size_t next = min_t(size_t, PAGE_SIZE, bytes); 243 244 if (page_folio(pages[j]) != folio || 245 pages[j] != pages[j - 1] + 1) 246 break; 247 unpin_user_page(pages[j]); 248 size += next; 249 bytes -= next; 250 } 251 252 bvec_set_page(&bvec[nr_bvecs], pages[i], size, offset); 253 offset = 0; 254 nr_bvecs++; 255 } 256 257 return nr_bvecs; 258 } 259 260 int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter) 261 { 262 struct request_queue *q = bdev_get_queue(bio->bi_bdev); 263 unsigned int align = blk_lim_dma_alignment_and_pad(&q->limits); 264 struct page *stack_pages[UIO_FASTIOV], **pages = stack_pages; 265 struct bio_vec stack_vec[UIO_FASTIOV], *bvec = stack_vec; 266 size_t offset, bytes = iter->count; 267 unsigned int direction, nr_bvecs; 268 int ret, nr_vecs; 269 bool copy; 270 271 if (bio_integrity(bio)) 272 return -EINVAL; 273 if (bytes >> SECTOR_SHIFT > queue_max_hw_sectors(q)) 274 return -E2BIG; 275 276 if (bio_data_dir(bio) == READ) 277 direction = ITER_DEST; 278 else 279 direction = ITER_SOURCE; 280 281 nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS + 1); 282 if (nr_vecs > BIO_MAX_VECS) 283 return -E2BIG; 284 if (nr_vecs > UIO_FASTIOV) { 285 bvec = kcalloc(nr_vecs, sizeof(*bvec), GFP_KERNEL); 286 if (!bvec) 287 return -ENOMEM; 288 pages = NULL; 289 } 290 291 copy = !iov_iter_is_aligned(iter, align, align); 292 ret = iov_iter_extract_pages(iter, &pages, bytes, nr_vecs, 0, &offset); 293 if (unlikely(ret < 0)) 294 goto free_bvec; 295 296 nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset); 297 if (pages != stack_pages) 298 kvfree(pages); 299 if (nr_bvecs > queue_max_integrity_segments(q)) 300 copy = true; 301 302 if (copy) 303 ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes, 304 direction); 305 else 306 ret = bio_integrity_init_user(bio, bvec, nr_bvecs, bytes); 307 if (ret) 308 goto release_pages; 309 if (bvec != stack_vec) 310 kfree(bvec); 311 312 return 0; 313 314 release_pages: 315 bio_integrity_unpin_bvec(bvec, nr_bvecs); 316 free_bvec: 317 if (bvec != stack_vec) 318 kfree(bvec); 319 return ret; 320 } 321 322 static void bio_uio_meta_to_bip(struct bio *bio, struct uio_meta *meta) 323 { 324 struct bio_integrity_payload *bip = bio_integrity(bio); 325 326 if (meta->flags & IO_INTEGRITY_CHK_GUARD) 327 bip->bip_flags |= BIP_CHECK_GUARD; 328 if (meta->flags & IO_INTEGRITY_CHK_APPTAG) 329 bip->bip_flags |= BIP_CHECK_APPTAG; 330 if (meta->flags & IO_INTEGRITY_CHK_REFTAG) 331 bip->bip_flags |= BIP_CHECK_REFTAG; 332 333 bip->app_tag = meta->app_tag; 334 } 335 336 int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta) 337 { 338 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); 339 unsigned int integrity_bytes; 340 int ret; 341 struct iov_iter it; 342 343 if (!bi) 344 return -EINVAL; 345 /* 346 * original meta iterator can be bigger. 347 * process integrity info corresponding to current data buffer only. 348 */ 349 it = meta->iter; 350 integrity_bytes = bio_integrity_bytes(bi, bio_sectors(bio)); 351 if (it.count < integrity_bytes) 352 return -EINVAL; 353 354 /* should fit into two bytes */ 355 BUILD_BUG_ON(IO_INTEGRITY_VALID_FLAGS >= (1 << 16)); 356 357 if (meta->flags && (meta->flags & ~IO_INTEGRITY_VALID_FLAGS)) 358 return -EINVAL; 359 360 it.count = integrity_bytes; 361 ret = bio_integrity_map_user(bio, &it); 362 if (!ret) { 363 bio_uio_meta_to_bip(bio, meta); 364 bip_set_seed(bio_integrity(bio), meta->seed); 365 iov_iter_advance(&meta->iter, integrity_bytes); 366 meta->seed += bio_integrity_intervals(bi, bio_sectors(bio)); 367 } 368 return ret; 369 } 370 371 /** 372 * bio_integrity_advance - Advance integrity vector 373 * @bio: bio whose integrity vector to update 374 * @bytes_done: number of data bytes that have been completed 375 * 376 * Description: This function calculates how many integrity bytes the 377 * number of completed data bytes correspond to and advances the 378 * integrity vector accordingly. 379 */ 380 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done) 381 { 382 struct bio_integrity_payload *bip = bio_integrity(bio); 383 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); 384 unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9); 385 386 bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9); 387 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes); 388 } 389 390 /** 391 * bio_integrity_trim - Trim integrity vector 392 * @bio: bio whose integrity vector to update 393 * 394 * Description: Used to trim the integrity vector in a cloned bio. 395 */ 396 void bio_integrity_trim(struct bio *bio) 397 { 398 struct bio_integrity_payload *bip = bio_integrity(bio); 399 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); 400 401 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio)); 402 } 403 EXPORT_SYMBOL(bio_integrity_trim); 404 405 /** 406 * bio_integrity_clone - Callback for cloning bios with integrity metadata 407 * @bio: New bio 408 * @bio_src: Original bio 409 * @gfp_mask: Memory allocation mask 410 * 411 * Description: Called to allocate a bip when cloning a bio 412 */ 413 int bio_integrity_clone(struct bio *bio, struct bio *bio_src, 414 gfp_t gfp_mask) 415 { 416 struct bio_integrity_payload *bip_src = bio_integrity(bio_src); 417 struct bio_integrity_payload *bip; 418 419 BUG_ON(bip_src == NULL); 420 421 bip = bio_integrity_alloc(bio, gfp_mask, 0); 422 if (IS_ERR(bip)) 423 return PTR_ERR(bip); 424 425 bip->bip_vec = bip_src->bip_vec; 426 bip->bip_iter = bip_src->bip_iter; 427 bip->bip_flags = bip_src->bip_flags & BIP_CLONE_FLAGS; 428 bip->app_tag = bip_src->app_tag; 429 430 return 0; 431 } 432